The 67-year-old retired Olympian - who was formerly known as Bruce Jenner before transitioning two years ago - stirred up controversy during an appearance on 'The Ellen Degeneres Show' in 2015 when she claimed she believed marriage should be between a man and woman, but has now said she fully supports the idea of same sex couples tying the knot.

Caitlyn - who has been married three times to Chrystie Jenner, Linda Thompson, and Kris Jenner - said: ''I am 100 percent behind gay marriage. Let's clear that up right now.''

The 'I Am Cait' star admitted the process had been an ''evolving'' one, but said she is now ''all for'' gay marriage.

And the star also spoke about her support for US president Donald Trump, but said her backing only comes as long as he doesn't ''mess with [her] community''.

She said: ''Yes, I did vote for Trump but here's the deal breaker with the Republican party. And the deal breaker is, you mess with my community, you do the wrong thing with our community, you don't give us equality and a fair shot, I'm coming after you.''

Caitlyn claims Donald even invited her to play golf with him, but she says she won't be taking him up on his offer.

She added: ''When I was at the inauguration I did say hi at a cocktail party, and he wanted me to play golf with him. At the time I thought it was a pretty good idea but since Title IX [which relates to the rights of LGBT people when it comes to education and Federal financial assistance] it's not a good idea and so I won't be playing golf with him.''

Caitlyn - whose new memoir 'Secrets of My Life' is due out on April 25 - also said she's pushing for ''federal guidance'' within the LGBT community, as she wants to see transgender people serving in the military.

Speaking in a preview clip for her '20/20' interview on American television network ABC which airs on Friday (21.04.17), Caitlyn said: ''When it comes to all equality issues, for the entire LGBT community, what we need is federal guidance. Just like the previous administration said that it was OK to serve as a trans person in the military. We have frontline people, OK? I'm talking Marines, trans guys, on the frontline, fighting for our country. I'm trying to get, especially the Republican party, to make a change.''